Epoxy-azido compounds

ABSTRACT

Disclosed are epoxy-azido compounds of the formula WHERE R is a polyvalent organic radical, R&#39;&#39; is a hydrogen, alkyl, cycloalkyl, aryl, or aralkyl radical, A is AND N AND M ARE INTEGERS FROM 1 TO 100. Also disclosed is the use of said epoxy-azido compounds in modifying polymers, crosslinking polymers, and adhering polymers to certain substrates, e.g., glass and other polymers.

Umted States Patent 1 3,608,604

[72] Inventor David S. Breslow 3,119,846 1/ 1964 Budde 260/348Wilmington, Del. 3,148,199 9/1964 De Groote et a1. 260/348 [211 App].No. 843,230 3,313,829 4/ 1967 Rosenblatt et al 260/348 [22] Filed July18, 1969 3,316,210 4/ 1967 Strother 260/47 [45] Patented Sept. 28, 19713,372,144 3/1968 Drucker 161/186 X [73] Assignee Hercules Incorporated3,449,200 6/1969 Kalafus et a1. 161/92 Wilmington PrimaryExaminer-Harold Ansher Assistant Examiner-C. B. Cosby s41 EPOXY-AZIDOCOMPOUNDS 1 Claim, No Drawings p 52 vs. C! 7 152/359 ABSTRACT: Disclosedare e x -azido com unds of the l17/138.8,156/110,156/330,16ll92,161/184:f l Po y Po 260/873 111:. CI 1160c 1/00, (R'-CH-CH)11R(AN;)m

C088 11/40, C08c 1 1/54 501 Field ofSenreh 161/231 where R is a Po] 1 yvent organlc rad1cal, R 1s a hydrogen, a1 184,185,186, 248,92; 156/110A,330; 152/330, k l alk l k l A 359; 260/348, 3, 873; 1l7/l38.8 y 0 y at y1 l 0 [56] References Cited g or UNITED STATES PATENTS 2,712,001 6/1955Greenlee 161/ 184 X and n and m are integers from 1 to 100. Alsodisclosed is the 2,741,607 4/1956 Bradley et al... 161/18 X use of saidepoxy-azido compounds in modifying polymers, 2,953,570 9/1960 Rudner260/348 cross-linking polymers, and adhering polymers to Certain Sub-3,014,895 12/1961 Reynolds et a1. 260/348 X strates, e.g., glass andother polymers.

where R is a polyvalent organic radical, R is a hydrogen, alkyl,cycloalkyl, aryl, or aralkyl radical, A is and n and m are integers,broadly each being 1 to 100, most preferably from 1 to 10. Generally, Rwill be an organic radical selected from the group consisting ofradicals derived by the removal of two or more hydrogen atoms fromalkanes such as, for example, ethane, propane, butane, isobutane,pentane and its isomers, hexane and its isomers, octane and its isomers,decane and its isomers, dodecane and its isomers, octadecane and itsisomers, and the like; cycloalkanes such as, for example, cyclopropane,cyclobutane, cyclopentane, cyclohexane, cyclooctane, and the like;alkylcycloalkanes, such as, for example, ethylcyclohexane,methylcyclobutane, and the like; arylenes, such as, for example,benzene, naphthalene, bipheny], and the like; alkyl substituted arylene,such as, for example, toluene, ethylbenzene, o-, mand p-xylene, mandpdiethylbenzene, and the like; alkylene-diarylenes, such as, forexample, diphenyl methane, 1,2-diphenylethane, l,l-diphenylpropane,l,3-diphenylpropane, 2,2-diphenylpropane, and the like;dialkylcycloalkanes such as, for example, 1,2-, 1,3- and1,4-dimethylcyclohexane, 1,2- and 1,3-dimethylcyclopentane, and thelike; the alkyloxyalkane, aryloxyarylene, alkaryloxy arylene, alkaryloxyalkarylene, aralkyloxyalkane, aralkyloxyaralkane, and the like; as wellas the corresponding thio and sulfonyl radicals, specific examples ofwhich include diethyl ether, propyl butyl ether, diphenyl ether,oxy-bis(pmethyl benzene), oxy-bis(phenyl methane), diethyl thioether,diphenyl thioether, diphenylmethyl thioether, butyl sulfonyl butane, andthe like radicals; and the foregoing radicals with fluoro, chloro,bromo, or iodo substituents. When an epoxyazido compound of thisinvention is to be used as a coupling or linking agent for polymers Rpreferably is substantially inert to the linking reaction.

Specific compounds of this invention represented by the foregoinggeneric formula include:

2,3-epoxybutyl azidoformate 9,10-epoxyoctadecyl azidoformate 4-(epoxyethyl)phenyl azidoformate 4-( epoxyethyl)phenylethyl azidoformate3-(epoxyethyl)benzyl azidoformate 3-cyclohexyl-2,3-epoxypropylazidoformate 4-phenyl-2,3-epoxybutyl azidoformate4-(2,3-epoxypropyl)phenyl azidoformate 2-(2,3-epoxypropyl)phenylazidoformate 4-(epoxyethyl)cyclohexyl azidoformate 2,3-epoxypropylazidoformate 9, l O-epoxydecyl azidoformate 9, l O-epoxydecyl-Z,5-diazodoformate 2,3-epoxypropyloxypropyl azidoformate2,3-epoxypropane-l-sulfonyl azide 4-(epoxyethyl)benzenesulfonyl azide5,6-epoxyhexanel -sulfonyl azide 7,8-epoxyoctane-3-sulfonyl azide l l,l2-epoxydodecane-3,7-disulfonyl azide 9, l O-epoxyoctadecanel -sulfonylazide 2,4-bis(epoxyethyl)cyclohexanel -sulfonyl azidel-(3,4-epoxycyclohexyl)ethane-2-sulfonyl azide 4-(3,4-epoxybutyl)benzenesulfonyl azide 2-(3,4-epoxybutyl)benzene sulfonyl azide4-(2,3-epoxypropyl)benzene sulfonyl azide 4-(2,3-epoxypropyl)benzenel,3-disulfonyl azide 2,3-epoxypropyloxypropyl sulfonyl azide.

The epoxy-azides of this invention range from liquids to solids at roomtemperature and atmospheric pressure and are soluble in chlorinatedhydrocarbons, aromatics, acetone, etc. They have a characteristicinfrared spectrum with a strong azide peak around 2,l35 cm". When heatis applied to the compounds of this invention they decompose giving offnitrogen; as the temperature increases the overall decomposition rateincreases. The azidoformate and sulfonyl azide radicals of the compoundsreadily react with receptive polymers and combine therewith when heated.They also combine with ethylenically unsaturated hydrocarbon groups in avariety of compounds. In so doing, the epoxy portion of the compoundremains free and unreacted. While the epoxy portion is heat stable itreadily reacts when contacted with amines or carboxylic acids.

The epoxy-azido compounds of this invention can be prepared by variousmethods. Most preferably these compounds will be prepared by theepoxidation of an unsaturated azide compound with peracetic acid orperbenzoic acid. The reaction is usually carried out at a temperaturebelow C. in a solvent. Acetic acid is the most preferred solvent whenusing peracetic acid but other solvents can be used such as methylenechloride, acetone, ethyl acetate, chloroform, benzene, and the like.

As indicated above this invention includes the use of the uniqueepoxy-azido compounds in modifying polymers, crosslinking polymers andadhering polymers to certain substrates. All of these uses involve thereaction of the azido portion or portions of the epoxy-azide compoundswith a receptive polymer. In this specification receptive polymer meansa polymer having in each polymer chain at least one and generally morethan one monomer unit capable of combination reaction with an azidoradical of a compound of this invention, whereby the residue of thecompound is chemically bonded to the polymer. Nearly all polymers arereceptive polymers. Preferred examples of a receptive polymer includeall types of hydrocarbon polymers including saturated and unsaturated,linear and nonlinear, crystalline and amorphous, homopolymers,copolymers, terpolymers, and the like; for example, polyethylene,polypropylene, polystyrene, styrene-butadiene rubber, butyl rubber,natural rubber, polybutadiene, polyisobutylene, ethylene-propylenecopolymer, cis-l,4- polyisoprene, ethylenepropylenedicyclopentadieneterpolymer, and the like; and blends of these polymers with each otherand blends of these polymers with organic nonhydrocarbon polymers. inaddition to hydrocarbon polymers preferred examples of a receptivepolymer include a large number of organic nonhydrocarbon polymersincluding homopolymers, copolymers, terpolymers and the like. Typical ofthese organic nonhydrocarbon polymers are cellulose esters, such as, forexample, cellulose acetate-butyrate, cellulose acetatepropionate,cellulose acetate, cellulose propionate, cellulose butyrate, and thelike; cellulose ethers, such as, for example, hydroxyethyl cellulose,hydroxypropyl cellulose, and the like; polyesters such as poly(ethyleneglycol terephthalate), drying and nondrying alkyd resins and the like;poly(alkylene oxide) polymers, such as poly(ethylene oxide),poly(propylene oxide), oxide), poly(ethylene oxide-propylene oxide);polyamides such as nylon, and the like; allyl pentaerythritolderivatives such as, for example, the condensate of triallylpentaerythritol with diallylidene pentaerythritol, esters of triallylpentaerythritol and drying oil fatty acids, and the like; poly(vinylalkyl ethers) such as, for example, poly(vinyl methyl ether) and thelike; poly(vinyl acetals) such as, for example, poly(vinyl butyral) andthe like; vinyl chloride polymers having a vinyl chloride content of atleast 10 mole percent, such as, for example, poly(vinyl chloride), vinylchloride-vinyl acetate copolymers, vinyl chloride-vinylidene chloridecopolymers, vinyl chloride -fumaric acid copolymers, vinyl chloridevinylacetal copolymers, such as, for example, the vinyl chloridevinyl butyralcopolymers, vinyl chloridevinylidene chloride-acrylonitrile terpolymers,and the like; nitrocellulose; chlorinated natural rubber;sulfochlorinated polyethylene; polysulfide rubber; polyurethane rubber;poly(vinyl acetate); ethylene-vinyl acetate copolymers; poly (vinylidenechloride); vinylidene chloride-acrylonitrile copolymers; ethylacrylate2-chlorethyl vinyl ether copolymers; poly (ethyl acrylate);poly(ethyl methacrylate); poly[3,3-bis(chloromethyl)oxetane];vinylmodified poly(dimethylsiloxane); polychloroprene;butadieneacrylonitrile copolymers; and the like.

The modified polymers of this invention resulting from the reaction ofthe azido portion or portions of the epoxy-azido compounds with theabove receptive polymers are both useful in themselves and necessaryintermediates in further modifications of this invention. The amount ofepoxy-azido compound used to modify a receptive polymer will depend uponthe desired end use. In general, however, the amount will be from about0.01 to about 40 percent by weight based on the weight of the polymer.The resulting modified polymers are quite stable and generally havephysical properties similar to the unmodified polymers. However, thethus modified polymers exhibit new and improved static properties,adhesion properties, launderability, etc. Modification can be carriedout by admixing the required amount of epoxy-azido compound with areceptive polymer and heating to a temperature sufficient to react theazido portion or portions of the compound with the polymer. In the caseof epoxy-sulfonyl azide compounds this temperature will be in the rangeof from about 120 to about 240 C. In the case of epoxy-azidoformatecompounds the temperature will be in the range of from about 80 to about200 C.

In one modification of this invention the epoxy-azido compounds are usedto bond various polymers to a substrate selected from siliceousmaterials, metals and other polymers. A typical example of the bondingprocess of this invention is the bonding of an a-olefin polymer such aspolypropylene to a glass substrate. The said glass substrate, such asglass fibers, glass cloth, plate glass, etc., would first be treatedwith an amino silane compound. In so doing, the silane portion of thecompound would react with the substrate, leaving the amine portion freefor later reaction with an epoxy portion of an epoxy-azido compound.Next, polypropylene, having been modified with an epoxy-azido compoundso as to react the azido portion with the polymer leaving the epoxyportion free, is placed in contact with the above-described treatedglass. The free amine groups on the treated glass react with a freeepoxy group on the modified polymer forming a tight bond between thepolymer and the glass substrate.

Another typical example of bonding a polymer to a substrate using anepoxy-azido compound is the bonding of poly(ethylene terephthalate) tirecord to rubber tire stock. The polyester tire cord is first modifiedwith the epoxy-azido compound. In so doing the azido portion or portionsreact with the polyester leaving the epoxy portion or portions free.Next, the tire cord is generally coated with a conventional tire cordadhesive comprising a mixture of a phenol-aldehyde resin and a rubberterpolymer latex prepared from a vinyl aryl monomer, a diene monomer,and a vinyl pyridine monomer, and then cured. If desired, the coating ofconventional tire cord adhesive can be omitted with a proportionatedecrease in adhesive strength. Finally, the thus treated tire cord isembedded in a vulcanizable rubber tire stock and cured. While polyestertire cords are mentioned, it will be understood that various othersynthetic fibers can be incorporated in rubber tire stock in accordancewith this invention. Such other tire cord fibers are for example,polyolefin, polyamide, polycarbonate, rayon, etc., and mixtures of thesefibers. Improved adhesion of the synthetic fibers to the rubber tirestock can be obtained by the process of this invention no matter whatthe physical form of the fibers e.g., monofilament, multifilament,twisted, braided, etc. The tire cord can be treated with the epoxy-azidocompound by any conventional means, for example, by dipping, spraying,brushing, or running the cord over a coated roll with a solution of theepoxy-azido compound in a suitable liquid. The epoxy-azido compound canalso be applied as an aqueous suspension, emulsion, or dispersion. Afterthe epoxy-azido compound is applied, the cord is heated to a temperatureat which the azido portion or portions react with the synthetic fiber.Various amounts of the epoxy-azido compound can be used. The optimumamount will depend upon the amount of modification desired, the specificepoxy-azido compound used, etc. In general, the amount added, based onthe cord, will be from about 0.1 to about 10 percent by weight. Asindicated above, the thus modified cord is generally coated with aconventional tire cord adhesive. This adhesive comprises a mixture of l)a resin, preferably prepared from resorcinol and formaldehyde with (2) aterpolymer latex, which is preferably a styrene-butadiene-vinyl pyridineterpolymer. The vinyl pyridine content of the terpolymer is usuallyabout 5 to about 25 percent, the styrene content about 5 to about 35percent, and the butadiene content from about 50 to about percent. Thelatex is applied to the modified tire cord by dipping, spraying,brushing, running the modified cord over a coated roll or otherconventional procedure. The amount of latex added will be from about 2to about 10 percent based on the weight of the cord. The thus coatedcord will be cured at a temperature of from about to about 235 C. for aperiod of time of from about 0.5 to about 2 minutes. The thus treatedcord is then embedded in a conventional rubber tire stock and curedunder pressure. The vulcanizable tire stocks in which the treated cordcan be embedded as a reinforcing medium include natural rubber, andsynthetic rubbers such as styrenebutadiene rubbers,ethylenepropylene-diene terpolymer rubbers, polybutadiene, polyisopreneand mixtures and blends thereof with suitable fillers, pigments,antioxidants, and crosslinking (i.e. vulcanizing) agents such as sulfur,peroxides, etc.

Another typical example of bonding a polymer to a substrate using anepoxy-azido compound is the bonding of an aolefm polymer such aspolyethylene to a metal substrate. The metal substrate will first betreated with a priming agent. The priming agent is a polyfunctionalcompound, such as an amino silane compound, which possesses a portion orportions which bond to the metal and another portion or portions whichremain free to react with the epoxy group or groups on the epoxy-azidocompounds. The process of bonding polyethylene to a metal substrate canbe carried out in various ways. For example, the substrate can be coatedwith a solution or suspension of the priming agent, allowed to dry, thencoated with a solution or suspension of the epoxy-azido compound,allowed to dry and finally contacted with the polyethylene at thedecomposition temperature of the azide. By another method, the substratecan be coated with a solution or suspension of the priming agent,allowed to dry, then contacted with a solution or mixture of both theepoxy-azido compound and the polyethylene and finally heated to thedecomposition temperature of the azide. By still another method thepriming agent, epoxy-azido compound and polyethylene can be depositedtogether on the substrate and then heated.

The substrates to which the polymers may be bonded in accordance withthis invention include siliceous materials such as glass, asbestos,sand, clay, concrete, stone, brick, ceramic materials, etc.; metals suchas aluminum, cadmium, chromium, copper, magnesium, nickel, silver, tin,iron, titanium, zinc, etc., alloys of the metals such as steel, brass,bronze, nickel chrome, etc. and including metals which have beensurface-treated with phosphates, chromates, etc. or on the sur face ofwhich oxides have formed; and other polymers. By the term otherpolymers" is meant any polymer other than the polymer to which it is tobe bonded. These substrates to which the polymers may be bonded can bein various forms such as sheets, plates, blocks, wires, cloth, fibers,particles, etc.

In another modification of this invention the epoxy-azido compounds areused to cross-link receptive polymers. The polymer to be cross-linked isadmixed with from about 0.1 to about 20 percent by weight of anepoxy-azide compound and heated to a temperature sufficient to react theazido portion or portions of the compound with the polymer. To affectcrosslinking the thus modified polymer is treated with a polyfunctionalcompound which will react with the free epoxy groups on the polymer.Various polyfunctional compounds can be used to affect thecross-linking, however, most preferred are the polycarboxylic acids andanhydrides, such as oxalic acid, phthalic acid, phthalic anhydride,pyromellitic anhydride, etc. and the polyamines, such asm-phenylene-diamine, diethylenetriamine, 4,4-methylenedianiline, etc.When using one of these compounds, the carboxylic acid groups or aminogroups react with the free epoxy groups tying together, i.e.cross-linking, the polymer chains.

The following examples will serve to illustrate the invention, all partsand percentages being by weight unless otherwise indicated.

Example 1 This example illustrates the preparation of 2,3 epoxybutylazidofonnate.

To a slurry comprising 1 parts of sodium azide, 200 parts of water, 158parts of acetone and 670 parts methylene chloride was added 115 parts ofcrotyl chloroforrnate with rapid stirring at room temperature. Afterstirring for 24 hours the orange-colored reaction mixture was dilutedwith 200 parts of water, separated, the organic layer washed with water,and dried over sodium sulfate. Removal of the solvent at roomtemperature yielded 1 12 parts of a clear colorless oil comprisingcrotyl azidoformate. A solution of 50 parts of the crotylazidoformate in420 parts of glacial acetic acid and 3 parts of anhydrous sodium acetatewas cooled to 20 C. To the crotyl azidoformate solution was added withagitation, 40 percent peracetic acid in an amount in excess of thatrequired to convert the crotyl groups to epoxybutyl groups. The reactionwas allowed to slowly come to room temperature and stirred until thetheoretical amount of peracetic acid had been consumed. The reactionmixture was tested periodically to determine the amount of peraceticacid present. At the end of the fourth day the reaction was diluted with600 parts of water and then extracted twice with 400 parts of methylenechloride. The methylene chloride solution was in turn washed with waterand then dried over sodium sulfate. After removing the solvent 47 partsof 2,3-epoxybutyl azidoformate was obtained. The product waslight-colored oil. Analysis for azide by nitrogen evolution showed thatthe compound contained approximately 98.7 percent of the theoreticalamount. An analysis for oxirane oxygen showed that the compoundcontained approximately 91 percent of the theoretical amount. A typicalinfrared spectrum of this product displayed a strong azide peak at 2,135cm.

Example 2 This example illustrates the preparation of9,10-epoxyoctadecyl azidoformate.

Oleyl azidoformate was prepared from oleyl chloroformate using sodiumazide as described in example 1. A solution of 84.5 parts of the oleylazidoformate in 420 parts of glacial acetic acid containing 2 parts ofsodium acetate was cooled to 20 C. To this solution was added withagitation, 40 percent peracetic acid in an amount in excess of thatrequired to convert the oleyl groups to epoxyoctadecyl groups. Thereaction was followed by testing for the presence of peracetic acid.After 7 hours the reaction had ceased as indicated by the disappearanceof peracetic acid. After 24 hours the reaction was diluted with 800parts of methylene chloride and 600 parts of water. The methylenechloride layer was washed with water six times and then dried oversodium sulfate. Removal of the methylene chloride solvent left 82 partsof a colorless oil consisting essentially of 9,10-epoxyoctadecylazidoformate. Analysis for the presence of azide by nitrogen evolutionshowed that the compound contained approximately 96 percent of thetheoretical amount.

Example 3 This example illustrates the preparation of the epoxidationproduct of the azidoformate of the triallyl ether of pentaerythritol.

To a solution of 43 parts of the azidoformate of the triallyl ether ofpentaerythritol in 315 parts of glacial acetic acid containing 1 part ofsodium acetate at room temperature was added with agitation percentperacetic acid in an amount in excess of that required to convert one ofthe allyl groups to an epoxy group. After stirring for 48 hours thereaction was diluted with 750 parts of water and 535 parts of methylenechloride. The methylene chloride layer was removed and washed with waterfive times and then dried over sodium sulfate. Removal of the methylenechloride solvent left 39 parts of clear colorless oil consistingessentially of the epoxidation product of the azidoformate of thetriallyl ether of pentaerythritol. Analysis of the product indicatedthat is contained 13.6 percent azido nitrogen and 4.2 percent oxirane oxygen.

Example 4 This example illustrates the preparation of2,3-epoxypropanel-sulfonyl azide.

To a solution of 14.7 parts of 2propene-l-sulfonyl azide in 105 parts ofglacial acetic acid containing 1 part of sodium acetate was added withstirring at room temperature 40 percent peracetic acid in an amount inexcess of that required to convert the propene radical to anepoxypropane radical. The reaction was stirred at room temperature untilthe peracetic acid content remained constant and then diluted with 200parts of water and parts of methylene chloride. The methylene chloridelayer was removed and washed with water five times and then dried overmagnesium sulfate. The methylene chloride solvent was removed leaving15.1 parts of 2,3-epoxypropane-l-sulfonyl azide. The results of aninfrared analysis of the product for percent azido nitrogen and oxiraneoxygen is tabulated below:

Calculated Example 5 This example illustrate the preparation of4-(epoxyelthyl)benzenesulfonyl azide.

To a slurry of 17.5 parts of sodium azide in 20 parts of water and 40parts of acetone at room temperature was added with rapid stirring asolution of 18 parts of p-styrenesulfonyl chloride in 61 parts ofmethylene chloride. After stirring at room temperature for 18 hours theorange-colored reaction mixture was diluted with parts of water andseparated. The water layer was reextracted with 61 parts of methylenechloride and then the combined methylene chloride layers were washedwith water and dried over magnesium sulfate. After removal of themethylene chloride solvent 12 parts of the resulting p-styrenesulfonylazide was dissovled in l 10 parts of glacial acetic acid containing 1part of sodium acetate at 20 C. To the solution was added with agitation40 percent peracetic acid in an amount in excess of that required toconvert the styrene group to an epoxy ethyl benzene group. The reactionwas allowed to come to room temperature and stirred until the peraceticacid content remained constant. Then it was diluted with 250 parts ofwater and 133 parts of methylene chloride. The methylene chloride layerwas removed and washed six times with water and then dried over sodiumsulfate. The methylene chloride solvent was removed to give 12.5 partsof 4-(epoxyethyl)benzenesulfonyl azide. The product was analyzed byinfrared analysis for azide nitrogen and oxirane oxygen. The results ofthis analysis are tabulated below:

Found Calculated b N, l7.9 18.6 Oxirane oxygen 6.5 7.!

Example 6 This example illustrates the use of the epoxysulfonyl azide ofexample in cross-linking polyethylene.

A slurry of 100 parts of high density polyethylene, 0.5 part4,4'4'-thio-bis(6-tertiary-butyl-m-cresol) antioxidant and 5 parts4-(epoxyethyl)benzenesulfonyl azide in acetone was prepared. The acetonewas removed at 50 C. and the polymer reacted with the epoxy-azide byheating at 170 C. for 30 minutes. Ten parts of the thus modifiedpolyethylene was admixed with 0.15 part diethylenetriamine on a two-rollmill and then heated for 30 minutes at 160 C. A control sample of thepolymer was treated exactly the same way except for the addition of theepoxy-azido compound. The yd., samples were tested for cross-linking bysoaking in decahydronaphthalene at 140 C. The sample containing theepoxy-azide was insoluble in the decahydronaphthalene solvent,indicating crosslinking. The control sample, on the other hand, wascompletely soluble.

Example 7 This example illustrates the use of epoxy-azido compound ofexample 1 in bonding polypropylene to glass cloth.

Twelve-ply laminates of glass cloth and polypropylene film were preparedusing l8l-style electrical glass woven cloth, heat cleaned and having aweight of 8.9 ounces per sq. yd., and 5-mil film of crystallinepolypropylene having a melt index (I, at 230 C.) of 4.0. Sheets of theglass cloth were immersed in a benzene solution of'y-aminopropyltriethoxysilane and 2,3-epoxybutyl azidoformate. The twoingredients were present in the solution in approximately a 1:1 moleratio. The thus treated cloth was allowed to dry overnight and then laidup to form the laminate by alternating plies of the treated glass clothand sheets of the polypropylene film. The resulting assembly wascompression molded at a temperature of 220 C. for 5 minutes at contactpressure, 3 minutes at 220 C. under a pressure of 500 psi. and thencooled to 23 C. under 500 p.s.i. pressure to form a 'fli-inch-thicklaminate. A control laminate was prepared exactly as described aboveexcept for the omission of the epoxy-azido compound. Test specimens 1in. X3 in. were cut from the laminates and tested for flexural strengthaccording to ASTM D-790 on a 2-inch span at 0.05 in. per min. crossheadspeed. The results are tabulated below:

Flexural Strength (p.s.i.)

Treated sample Control Example 8 passed through two ovens in series at200 F. and 400 F. Residence times in the ovens were 65 and 54 secondsrespectively. The cord dip pickup was approximately 1 percent by weight.The modified cord was next coated with a conventional latex adhesive,prepared as follows: To a solution of 0.24 part of sodium hydroxide in192.8 parts of water was added 8.8 parts of resorcinol with continuedstirring until a complete solution was achieved. Then 12.2 parts of 37percents formaldehyde was added. The solution was aged for approximatelyfive hours at about 75 C. and then added slowly to a mixture of 48 partswater and 195 pans of a latex comprising a terpolymer of styrene,butadiene and vinyl pridine, the monomers being present in a ratio ofapproximately 50:70:15. The mixture was stirred slowly for 15 minutesand its pH adjusted to 10.3 using concentrated ammonium hydroxide. Theresulting gray-violet latex containing approximately 20 percent solids.The epoxy azido modified cord was passed twice through a trough of thelatex under a tension of 500 grams and then dried and cured for 54seconds at a temperature of 430 F.

The thus coated cord was then vulcanized with a rubber tire stock in theform of ifs-inch H-specimens. The rubber tire stock has the followingformulation:

Compounds Parts Natural rubber (smoked sheet) Styrene butadiene rubber20 Semireinforcing furnace black 25 Zinc Oxide 5 Stearie Acid 2Polytrimethyldihydroquinoline l Heavy pine tar 0.5 Benzothiazyldisulfide l Tetramethyl thiuram disulfide 0.l Sulfur 2.6

The test specimens were cured for 45 minutes at a temperature of 307 F.After several hours conditioning at room temperature the l-l-specimenswere pulled apart on a tester according to the procedure of ASTM D-213862T. An average (6 test specimens) of 35.7 pounds was required toovercome the tire cord-rubber adhesion. A control specimen treatedexactly the same as above except for the epoxy-azido modification of thetire cord gave an average of 12.6 pounds required to overcome the tirecord-rubber adhesion.

What I claim and desire to protect by Letters Patent is:

1. A vulcanized rubber tire reinforced with polyester tire cord, saidtire cord having been modified by heating with a small amount of anepoxy-azido compound having the formula where R is a polyvalent organicradical, R is a radical selected from the group consisting of hydrogen,alkyl, cycloalkyl, aryl, and aralkyl radicals, A is a radical selectedfrom the group consisting of l .0.-:i1 an ..S02

and n and m are integers from 1 to 100.

mg UNITED sTATE PATENT OFFICE CERTIFICATE CORRECTION Patent No- .608,604V Dated Inventor(a) David S. Breslow (Case 48) It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 2, line 8, also Column 5, line 51,

"2, 135 cm. should read -2l35 era C0lumn 6, line 18, "is" should read-it-- Column 7, line 11, "4,4 '4 should read -4,4

Column 7, line 19, "yd., should read -two- Signed and sealed this 11thday of April 1972.

(SEAL) Attest:

EDWARD M.F'LETCHEH,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

